The gas composition of a planet's atmosphere generally determines how much heat gets trapped in the atmosphere. For the dwarf planet Pluto, however, the predicted temperature based on the composition of its atmosphere was much higher than actual measurements taken by NASA's New Horizons spacecraft in 2015. A new study proposes a novel cooling mechanism controlled by haze particles to account for Pluto's frigid atmosphere.
The trans-neptunian belt contains four dwarf planets, among which Haumea stands out for its extremely elongated shape and rapid rotation. A stellar occultation makes it possible to establish the main physical characteristics of this previously little known body -- among which most surprising was the presence of a ring.